Electret holder for a radon gas detector



FIG. 1 is a side perspective view of our new design for an electret holder for a radon gas detector;

FIG. 2 is a side elevational view of our new design, the opposite side being identical; and,

FIG. 3 is a top plan view of our new design. 

The ornamental design for an electret holder for a radon gas detector, as shown and described. 